Apparatus for no-effort inhalation anesthesia



April 22, 1952 M. A. LOREDO APPARATUS FOR NO-EFFORT INHALATIONANESTHESIA Filed Jan. 19, 1949 1 m l ml m. wa W Jr m m HI n W N H N l NMH TM R Q H d W .8 1 aw Q m Ma v m ax PW. Q r J N I H Ti A s Q mm a Q A aW Patented Apr. 22, 1952 APPARATUS FOR NO -EFFORT INHALATION AN ESTHESIAMiguel Angel Loredo, Habana, Cuba Application January 19, 1949, Serial N0. 71,697 V In Cuba March 18, 1948 1 Claim.

This invention relates to apparatus for ad'- ministering gases employedin the application of inhalatory anesthesia, by the closed or confinedmethod. The invention is characterized and distinguished in that iteliminates mechanical obstacles which heretofore have been interposed inthe respiratory circuit of the apparatus. The invention, therefore,provides a no-effort inhalation method and apparatus in which thepatient needs only the kind of respiratory force of a person in normalrepose and forced respiration is eliminated.

One object of this invention is to provide means whereby the patient isenabled to breathe, freely and directly, the anesthetic mixture withinthe breathing bag of the apparatus while conserving the vital functionsof oxygenation and elimination of carbon dioxide. The patient isentirely relieved of the strain imposed in the use of prior apparatuswhich necessitated the patient forcing the gases to circulate over sodalime, for example, and through lengthy tubes, pipes, valves and otherparts of the apparatus.

Another object of this invention isto provide a novel and improvedbreathing bag having three communicating passages, namely an inletpassage for the admission into the bag of the purified gases from theabsorber unit together with the gases from the standard gas supply unit.Secondly, an outlet passage for the exit of the gases from the breathingbag to the absorber unit. Third, a passage connecting the breathing bagwith the face mask. The patient breathes the gases in the bag throughthis third passage.

It is a feature of this invention that the inlet and outlet passages ofthe breathingbag are located on opposite sides of the bag or spaced asfar apart as possible, while the breathing passage to the face mask islocated between the said inlet and outlet passages and in a position tointercept the gas current established within the bag from inlet tooutlet thereof. Another object is to include, in the absorption circuitof the apparatus, mechanical means for circulating the gases.

The invention is embodied in a no-eifort inhalation apparatus consistingof a closed circuit from which the external atmosphere is excluded andwhich comprises three intercommunicating circuits, namely therespiratory circuit including the patients respiratory system and thebreathing bag with the face mask. Second, an absorption circuit whichincludes a mechanical gas circulating device and the absorber which con--or tube 5.

tains the carbon dioxide absorption material. Third, a gas supply orfeeder circuit which includes apparatus of known character and functionfor supply anesthetizing gases.

Other objects, features and advantages of this invention willbe apparentfrom the following detailed discussion read together with theaccompanying drawing in which Fig. 1 is a diagrammatic illustration ofan apparatus embodying the invention, with parts in section.

Fig. 2 is a view of the breathing bag.

In the drawing the reference numeral I denotes the breathing bag whichis made of the same material as now used for standard breathing bags inanesthesia apparatus. The bag has a gas inlet passage at 2 and a gasoutlet passage at 3. The passages are spaced as far apart as isconvenient or practicable in the manufacture of the bag. In thepreferred construction illustrated the two passages. 2 and 3 are onopposite sides of the bag I. The bag is also formed with a face mask orattached to a face mask 4 to be placed over the face of the patient asshown. The face mask communicates directly with the interior of the bagthrough a nipple The latter is located between the inlet and outletpassages 2 and 3, respectively, in such a position that it interceptsthe gas current passing through the bag. In Fig. l the breathing passage5 is located close to the inlet passage 2 and almost diametricallyopposite the outlet passage 3.

The anesthetizing gases are supplied from a source of'supply comprisinggas mixing cylinders 6 and 1 provided with control devices andinterconnecting passages as shown at 8 and 9 respectively. Inasmuch asthe gas supply unit is of known construction and function, no furtherdescription is deemed necessary. The gases pass from the supply unit tothe breathing bag by way of a connecting tube Ill and a second tube ll.At the point l2 the gas supply circuit is connected to the absorptioncircuit by a tube I3.

The absorption circuit comprises an absorber ,M which contains carbondioxide absorbing material indicated at IS. The exhaled gases from thebreathing bag I pass to the absorber M by way of a tube I 6. 'I he gasesthen pass through the material I5 and are drawn therefrom by asuction-impulse device in the form of a double pump having two bellowsl1 and I8 which are, alternately compressed and expanded by theoperation of connecting rods 19 and 20, which in turn are reciprocatedby cranks 2i and 22 mounted upon a shaft 23 180 degrees apart as shown.The shaft 23 is rotated by a motor 24 which drives a small pulley 25which is in driving engagement with a large pulley 26 secured to theshaft 23.

The space Within the bellows I1 is connected by a forked tube 28 to twovalve chambers 29 and 30 which contain valves 3i and 32. The spacewithin the other bellows I8 is connected by a forked tube 34 to twoother valve chambers 35 and 36 which contain valves 38 and 39. The valvechambers and valves are connected to the outlet side of the absorber Mby a suction tube 40. The valve chambers 29 and "36 are connected by atube 42 which communicates with the aforesaid tube 13.

Thus the suction side of the valve mechanism 28-39 is connected to theabsorber It by the tube 40. The supply side or outlet side of the valvemechanism is connected to the breathing bag by the tubes 42,13 and H.The gas circuits are indicated by arrows in the drawing.

The operation of the system is as follows: Gas flowing from the supplyunite-1 passes :to the breathing bag I through the tubes 10 and Handinlet :passage 2. The gas flows out of the bag through outlet passage 3and tube It: to the absorber 14. If new the motor 24 is started, theconnecting rods (9 and 20 will be operated and reciprocated toalternately compress and expand the pump bellows; li and it. Thus avacuum is created in the tube 40 and the exhaled gases are drawn throughthe material l in the absorber N where they are freed from carbondioxide and thereafter circulated through the valve mechanism 28-39 andthrough the outlettube '42 and 13 into the gas supply circuit from theunit 3-1. The purified gases from the absorber mingle with the gasesfrom the supply unit and pass through the tube 1 I into the bag.

The valves in the valve chambers are shown in open and closed positionscorresponding to the operations of the pump bellows I1 and 18. When thebellows ii are expanded, gas fiows'from the absorber l4 through openvalve 32 and forked tube 28 into the bellows ,l'i, valves 31 and 35being then closed. On the other side, the impelling movement of thebellows it forces the gas which had previously passed into the bellowsl8 out of the valve mechanism through forked tube 34,

' open valve 39 and tube d2. So that, by the ex clusive operation of thepump |1,l8 the purified gases are drawn from the absorber l4 andcirculated back into the breathing bag, the withd'rawal and circulatingrequiring no effort what- 's'oever from the breathing efforts of thepatient. -yIn the operation of the apparatus of the invention as hereindisclosed the anesthetic gases and oxygen are administered as in theknown closed standard systems. The absorber of the carbonic gas whichforms the greatest obstacle has been separated from the respiratorycircuit;

and placed inconnection with an aspirating and tion thereof may bechanged. The pump may be connected in the absorber circuit between thebag and the absorber, or between two absorbers, if such be used. Thebreathing bag may consist of more than one bag.

From the foregoing description and the drawing it will be clear that theinvention includes two'ess'ential elements, namely mechanical means forforcibly circulating the gases through the absorberand entirelyindependentof the breathing efforts of the patient, and the use of abag-mask of suitablesize and provided with communicating passages sointerrelated that the patient. is .provided with a breathing space andatmosphere which allow him to breathe without effort.

I claim:

An apparatus for administering anesthetic gases in a closed'circuit fromwhich the atmosphere is excluded, comprising an ,ela'sticibreathingbag-having an inlet, an outlet and a breathing passage, a carbon dioxideabsorber having an inlet and an outlet, ,a tube connecting saidbreathing bag outletwith theinlei; of said carbon dioxide absorber, apumping device having :an inlet and a discharge port, a second tubeconnecting the outlet of said carbondioxideabsorber with the'inlet'ofsaidpumping device, athird'tube connecting said'discharge port of saidpumping device with the inlet of said breathing bag, an

anesthetic gas supply source, a fourth tube connecting'said anestheticgas supplyintosa'id third tube connecting said .pumping device with thebreathing bag inlet, "said fourth .tube "discharging the anestheticgases coming'fromisaidgas supply source into said third tube at apointin the latter between the. discharge :port of said pumping deviceand said breathing bag inlet, and means for actuating said pumpingdevice.

. MIGUEL ANGEL LOREDO.

REFERENCES CITED The rfollowing references are of record in the file ofthis patent:

UNITED STATES PATENTS

